Ivan and Tim had 119 staplers together. Ivan had 13 more staplers than Tim. Both of them sold some of their staplers. Tim sold 10% less staplers than what Ivan sold. In the end, Tim had half as many staplers left as Ivan. How many staplers had Ivan left?
| |
Ivan
(1) |
Tim
(2) |
Make p the same
(2)x2 = (3) |
Comparing Ivan
and Tim at first |
13 more |
|
|
| Before |
66 |
53 |
106 |
| Change |
- 10 u |
- 9 u |
- 18 u |
| After |
2 p |
1 p |
2 p |
Number of staplers that Tim had at first
= (119 - 13) ÷ 2
= 106 ÷ 2
= 53
Number of staplers that Ivan had at first
= 53 + 13
= 66
Number of staplers that Tim sold in percent
= 100% - 10%
= 90%
90% =
90100 =
910 Make p the same.
(1) = (3)
66 - 10 u = 106 - 18 u
18 u - 10 u = 106 - 66
8 u = 40
1 u = 40 ÷ 8 = 5
Number of staplers that Ivan had left
= 66 - 10 u
= 66 - 10 x 5
= 66 - 50
= 16
Answer(s): 16
